First a caveat; the patent says, "The individual contributions of the separate insulative materials is not completely understood..."
In this configuration, Insul-Bright would provide about the same R Value as a 1/8" Thinlight. I don't have the time to get into the radiation computation details but, the degree to which the IR component of Insul-bright insulates is dependent on both the orientation and distance from the heat source.
Insul-Bright is primarily used for hot pads and cozies. In this environment it competes with CCF and Thinsulate. Thinsulate uses the same big polyester fibers that you can see in my Insul-Bright photos. They augment that with very fine and dense polypropylene fibers. These fine polypropylene fibers accomplish the same thing as the Mylar, when used in a close proximity application hot pads, cozies, and near contact under covers.
In summary, for close proximity applications like hot pads, cozies, and bottoms of hammocks, Insul-Bright is generally equivalent to CCF or Thinsulate alternatives of similar thickness.